Hubble Spies on a Beautifully Messed-Up Galaxy

Galaxies come in all shapes and sizes, but can generally be grouped into easily identifiable regular shapes, such as the elegant spirals or run-of-the-mill ellipticals. And then there are the irregular galaxies, which account for roughly a quarter of known galaxies, that are just kinda messy.

In this recent Hubble Space Telescope observation, one such irregular galaxy, located around 16 million light-years from Earth, has been observed. It looks like a loose collection of stars that have been thrown together and shuffled, like my end-of-semester university dorm room. But this galaxy, called NGC 5408, isn't just a scattering of stars, it's a whole galaxy and it's a galaxy with some interesting astronomical history.

Originally discovered by British astronomer and mathematician John Herschel in June 1834, NGC 5408 was presumed to be a planetary nebula -- a gaseous cloud of gas generated by a dying star. But as astronomical optics improved, its true nature was revealed; NGC 5408 is an entire galaxy living by its own rules, refusing to conform to a regular shape.

Intermediate-mass black holes (or IMBHs) are the "middleweight" black holes that are thought to be the missing evolutionary link between puny stellar mass black holes and the gargantuan supermassive black holes. They are, however, very hard to find and astronomers are currently keeping tabs on ultraluminous X-ray sources in the hope that they may signal the presence of these mid-sized black holes.

. Since its launch in 1990, the veteran observatory has studied countless galaxies, but some of the most striking images are that of the majestic spirals that pervade the entire observable universe. In this celebration of spiral galaxies and Hubble's prowess at imaging them, we've collected some of our favorite galactic views from the space telescope's archives.

is undergoing some violent gravitational disturbances after a suspected galactic collision. The creation of the stream of stars post-collision appear as a tail, giving the galaxy "The Tadpole" moniker.